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Is fructose being blamed for the obesity epidemic when the real problem is we just ingest too many calories?

Toronto, February 21, 2012

By Leslie Shepherd

TORONTO, Ont., Feb. 21, 2012-- Is fructose being unfairly blamed for the obesity epidemic? Or do we just eat and drink too many calories?

Researchers from St. Michael’s Hospital reviewed more than 40 published studies on whether the fructose molecule itself causes weight gain.

In 31 “isocaloric” trials they reviewed, participants ate a similar number of calories, but one group ate pure fructose and the other ate non-fructose carbohydrates. The fructose group did not gain weight.

In 10 “hypercaloric” trials, one group consumed their usual diet and the other added excess calories in the form of pure fructose to their usual diet or a control diet. Those who consumed the extra calories as fructose did gain weight.

However, all that could mean is that one calorie is simply the same as another, and when we consume too many calories we gain weight, said the lead author, Dr. John Sievenpiper.

“Fructose may not be to blame for obesity,” he said. “It may just be calories from any food source. Overconsumption is the issue.”

Fructose is naturally found in fruits, vegetables and honey. Participants in the studies examined by Dr. Sievenpiper ate fructose in the form of free crystalline fructose, which was either baked into food or sprinkled on cereals or beverages.

The studies did not look at high-fructose corn syrup, which has been singled out as the main culprit for weight gain. It is only 55 per cent fructose, along with water and glucose.

Dr. Sievenpiper said the majority of studies they examined were small, of short-duration and of poor quality, so there is a need for larger, longer and better quality studies.

About St. Michael’s Hospital

St. Michael’s Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future health care professionals in more than 23 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, and care of the homeless are among the Hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Center, which make up the Li Ka Shing Knowledge Institute, research and education at St. Michael’s Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.